Front Tires

I have to disagree with Busa Dave on something. There are definitely V rated tires available for the front. Just look at any MC catalog. http://www.denniskirk.com/jsp/product_c ... GIJJBSI7S4
Also...I warn anyone against going faster than the speed rating of the tire. I've posted this before but several years ago I had my 104 rear wheel HP Harley stroker on a dyno and the asshole running it took it up to 160 mph at which time the Conti H rated rear tire I was running disintegrated completely in front of my eyes. I had admonished him not to exceed 5000 rpm but he just let it loose to well over 6000 with my 6 speed trans. The tread ballooned out and began to fly away from the carcass in pieces.
The tire had a few hundred miles on it.
I became a believer in speed ratings at that point. Most people understand these ratings as theoretical but I saw what they mean with these two eyes.
The higher speed rated tires are stiffer, have thinner treads for greater heat dissipation and are much less comfortable to ride but if you are in the groove of doing 145 or so, I wouldn't even consider an H rated tire....Joe

zenbiker said:

I have to disagree with Busa Dave on something. There are definitely V rated tires available for the front. Just look at any MC catalog.
Also...I warn anyone against going faster than the speed rating of the tire. I've posted this before but several years ago I had my 104 rear wheel HP Harley stroker on a dyno and the asshole running it took it up to 160 mph at which time the Conti H rated rear tire I was running disintegrated completely in front of my eyes. I had admonished him not to exceed 5000 rpm but he just let it loose to well over 6000 with my 6 speed trans. The tread ballooned out and began to fly away from the carcass in pieces.
The tire had a few hundred miles on it.
I became a believer in speed ratings at that point. Most people understand these ratings as theoretical but I saw what they mean with these two eyes.
The higher speed rated tires are stiffer, have thinner treads for greater heat dissipation and are much less comfortable to ride but if you are in the groove of doing 145 or so, I wouldn't even consider an H rated tire....Joe

Click to expand...

For the stock wheel the only size that is rated for the weight is a "cruiser type" tire. I have had many front y speed rated tires for my Hayabusa, Ducati and Bandit in the past but unfortunately, they are not the right size--just look in any motorcycle catalog. If they made it I would have it you can be assured of that because I do not like running the non y speed rated tires. I have talked with the several people in the tire industry about this (I have worked on several tire development contracts for different aircraft and know a few people at Goodyear (who owns Dunlop) and Michelin as well as the design engineers here) and the answer is simple= not enough demand period to justify the development costs. Also our bikes were not made to go over 130 and be safe or the correct tire would have been developed by BH and put on it.

I have been over 195 (215 indicated) for several miles at a time more times than I can remember on my Busa and it was smooth as silk (Duc would top out at 165) because it was designed to do that---my BH scares the crap out of me at 147 when the shift light comes on. The good part about the BH is it gets there quick now that I have modified it and the sound is without peer!!!

Found something interesting, thought I would share:
All tire ratings per ISO are at 40 degrees Centagrade, at rated PSI. Degrading the PSI also derates the tire by 15%
Additionally the Adhesion/peel/ aging test gave a life expencancy of the true rating of a tire for 3-4 years.

It’s equally important to pay attention to the speed rating of your tires, as it holds some very pertinent information about the overall performance of your wheels.

The International Standards Organization (ISO) utilizes a load/speed index code, which allows you to determine the correct size of tire you should purchase.

For instance, a tire speed rating will inform you about the weight or load amount a particular set of tires can hold at high speeds.

Here’s a look at the grade ratings that are used to indicate the top speed a tire can safely operate at:


M – up to 81 mph (130 kph)
N – up to 87 mph (140 kph)
P – up to 93 mph (150 kph)
Q – up to 99 mph (160 kph)
R – up to 106 mph (170 kph)
S – up to 112 mph (180 kph)
T – up to 118 mph (190 kph)
U – up to 124 mph (200 kph)
H – up to 130 mph (210 kph)
V – up to 149 mph (240 kph)
Z – speeds above 149mph (240 kph)
The Z rating turned out to be to vague, and so two more ratings were added:

W – up to 168 mph (270 kph)
Y – up to 186 mph (300 kph)

The load/speed index code will usually appear after the size marking on a tire, compromised by two numbers and a letter.

For instance, 67H is an example of a load/speed index code.

The numbers on this code refer to the maximum load carrying capacity of your tires. The letter that is used in conjunction refers to the speed rating, or maximum speed your tire can endure under load and inflation pressure.